Oven-heat regulator



Nov. 16 1926. 1,606,987

E. L. cLAUs OVEN HEAT REGULATOR Filed NOV. 10; 19 23 4 Sheets-Sheet lNov. 16 1926.

.E. L. CLAUS OVEN HEAT REGULATOR Filed Nov. 10. 1923 4 Sheets-Sheet 4 VM H m w Patented Nov. 16, 1926.

U'NlT STATES PATNT. orrica.

EMIL L. CLAUS, OF MILVVAU'KEE, WISCONSIN, ASSIGNOR, BY DIRECT AND.MESNEAS SIGNMENTS, T MILWAUKEE GAS sPEcIALTYscofMPANY, OF MILWAUKEE, WIS-CONSIN, A CORPORATION OF 'WISCONSIII.

OVEN-HEAT REGULATOR.

Application filed November 10, 1923. Serial No; 873,953.

This invention relates to certain new and useful improvements in ovenheat regulators capable of use on kitchen stoves, ranges and any otherdevice' where it is desired to maintain a predetermined degree of heatin a compartment such as an oven or any other .space. i

Various types of oven regulators have been designed and are on themarket and while they apparently function to some degree of certaintyand' accuracy, the are objectionable from the stove manu acturersstandpointin that they require specialpiping and fittings," materiallyincreasing the cost of 1n- 'stallation, and furthermore they arediificult to install on gas stoves not arranged for their installationat the time of manufacture.

Having this in mind, it is an objectof my. invention to provide an ovenheat regulator which eliminates thenecessity of roviding' special pipingand fittings material y simplifying its application to an oven or otherchamber. or compartment to beregulated, re-

ducin the time, labor and material required, and acilitating its readyapplication to stovesnow in use or to stoves at the timeof theirmanufacture.

Another feature which is objectionable in the oven heat regulators nowon the market: is that they are not designed to meet all stoveconstruction, and it is, therefore, another object of this inventiontoprovide an oven heat regulator which is capable ofi-application to alltypes of stoves without" requiring cated within the oven to beinfluenced by the special fittings or arrangements.

Another feature which is objectionable int the types of oven heatregulators now on the" market is, that special cratingmust be providedfor the shipment of the stove so equipped in that they project orprotrude from the oven and means must be provided to properlyaccommodate and 'protect the same.

This invention, therefore, contemplatesas another ofits objects torovide a the -mo; static instrument which stove, which is accommodatedin the standard crates of the various manufacturers and, therefore, therequirement of special crating is eliminated.

oes not protrude. from the oven beyond ,the stringerfof the the deviceto serious objections on the part of the stove manufacturers, the usersand the fire underwriters, and this invention has for another of itsobjects to provide an oven heat connected from the oven,'thus insuringan increased factor of safety in the operation thereof and eliminatingthe necessity of snug fittings and packing glands such 'as are necessarywith the other devices in order to reduce the possibility of the gaspassing into the oven to a minimum.

Another objectionable feature of the ther- -mostatic devices of. thecharacter described now or. the market is that they employ one or moresprings actin against a thermostatic member which tages in that aftercontinued use, the spring 'regulator'in which the gas is absolutelydisas many disadvane 'crystallizesand loses its strength throwing theinstrument out as far as accuracy is concerned and furthermore thesprlng is gen- .erally affected by the heat of the oven resultof thisinvention resides in the provision of a thermostatic member having ahigh co-eificient of expansion and 10 heat therein and acting againsta-member having a' low co-efiicient of expansion and located outwardlyof the oven within a neutral zone whereby the positiveness of theoperation of the device is increased.v Another object of this inventionresides in the provision of means permitting the circulation of airthrough the thermostatic member having a high co-eiiicient of exansion,-whereby the same quickly respon s to changes in temperature tothus increase the 'sensitiveness of the instrument.

Another object of this invention is to pro vide means for circulatingair through the member having a low co-efiicient of ex ansion to preventits being influenced by eat radiated from the oven and to thus increasethe efliciency and accuracy of the instrument.

Another object of this invention resides in the provision of a rotatableactuating dial requiring but one turn or less to adjust the instrumentfrom minimum to maximum heat.

'Another object of this invention resides in the provision of a devicehaving a compound dial whereby the regulator may be adapted for use witheither artificial or natural gas without requiring any change in theconstruction thereof.

Another object of this invention resides in the provision of a device,the thermostatic member of which works against the solid cast iron frontof the oven to thus insure accuracy of operation.

In thermostotic instruments for controlling oven temperatures, it isessential that an adjustable pilot light be provided and heretoforeconsiderable difficulty has been experienced'in that the adjustment forthe pilot light has been from a remote point resulting in frequentextinction of the pilot inasmuch as the gas pressure is reduced byexpansion in the pilot supply tube or pipe and it is, therefore, anotherobject of this invention to provide an improved pilotstructure whereinthe adjustment of the volume of gas supplied thereto is made at thepilot tube.

Another object of this invention resides in the provision of apilotlight having means located at the pilot tip, but operable from a remotepoint, for adjusting the pilot li ht.

Another object of this invention resides in the provision of a valvestructure including telescopng tube members actuated from a thermostaticmember influenced by the oven temperature, whereby the necessity of asnug leak-proof fit between the valve members is eliminated and,consequently, the necessity of lubricating the parts and the occurrenceof sticking avoided.

It is another object of this invention to provide a thermostaticinstrument for regulating the temperature of an oven having severalmeans of adjustment all of which are in convenient places exteriorly ofthe stove .where atmospheric conditions whereby the adjustments are notinfluenced in any manner by the oven heat.

Another object of this invention resides in the provision of a device ofthe character described wherein the action of the member influenced bythe oven heat is direct, wherethe provision of a thermostatic instrumentfor regulating the temperature of an oven in which it is unnecessary topenetrate the oven slde walls thus eliminating the consequent prevailincrease in losses due to crackin of the enamel such as is encounteredin t 1e manufacture of stoves where it is necessary that the side ovenpanels be penetrated in order to permit the instrument to enter theoven.

The prerequisites for a thermostatic mstrument to meet all prevailingconditions are accuracy, maintenance, economy and safety, and it is afurther object of this invention to provide an instrument of thecharacter described in which all of these essential features areincorporated.

A still further object of this invention resides in the provision of adevice which has provision for. horizontal, vertical and universaladjustment between it and the shut-off cock for the oven whereby thedevice may be readily adapted to any stove irrespective of the relationof the oven to the oven control valve. I

And a still further object of this invention resides in the provision ofa device of the character described wherein the drilling of only a smallhole in the front and rear oven walls and the substitution of a specialvalve for the conventional oven shut-oil cock isrequired for itsapplication to any make of oven.

With the above and other objects in view which will appear as thedescription proceeds, my invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

In the accompanying drawings, I have illustrated one complete example ofthe physical embodiment of my invention, and a modification thereof,constructed according to the best modes I have so far devised for thepractical application of the principles thereof, and in which:

Figure 1 is a perspective view of a portion of a gas stove or rangeillustrating the application thereto of an oven heat regulator embodyingthis invention;

Figure 2 is a side View of the controlling valve looking in the plane ofthe line 2-2 of Figure 3, the medial portion thereof being broken. away,and but a portion of the oven front frame being illustrated;

Figure 3 is a sectional view taken vertically throughthe valve structureat right angles to Figure 2 on the plane of the-line 3-3 thereof;

Figure 4 is a detail view, partly in vertical section and partly inelevation, of the lower portion of the control valve, said view beingtaken through Figure 7 on the plane of the line 4-4;

Figure 5 is a view in top plan illustrating the thermostatic members foractuating my device, the medial portion thereof being broken away andthe oven wall and the guard or covering for the forward ends of saidmembers being in section;

Figure 6 is a detail view of the adjustable pilot for the oven burner,said View being partly in section and partly in' side elevation, andtaken through Figure-,3 on the plane of the line 66;

Figure 7 is a view, partly in section and partly in; top plan, takenthrough Figure 2 on the plane of the line 77 Figure 8 is a detailsectional view illustrating the by-pass for insuring the maintenance ofa minimum flame at the oven burner, said view being'taken through Figure7 on the plane of the line 8-8;

Figure 9 is a fragmentary sectional view taken on the plane of the line9-9 of Figure 7, and

Figure 10 is a view similar to Figure 2 with the lower portion thereofbroken away and in section and illustrating a slightly modifiedconstruction of valve in which a reciprocal sleeve is employed in lieuof the 'rotating sleeve of that embodiment illustrated in Figures L to8, inclusive.

Referring now more particularly to the accompanying drawings, in whichlike nu merals designate like parts throughout. the several views, thenumeral 10 designates a heating oven which is provided at its front withthe usual door 11 communicating with the space 12 or oven proper, theoven may be of either the single or double wall type and has a frontframe 13 surrounding the opening closed by the door. 11 and which is ofsturdy material, such as cast iron, steel or the like, and extends alongthe top sides and bottom of the oven door opening and is suitablyconnected with the framework 14 of the range proper. The oven is heatedby a burner 15, illustrated by dotted lines in' Figure 1, of any desireddesign or construction and connected with a stringer pipe 16-, mountedat the forward portion of the frame 14, through a gas cock 17, to belater more specifically d scribed, and a manifold 18.

The rig-id ame-work 13 of the oven is of such construction as to havepractically no contraction or expansion under the ranges of temperatureat which the ordinary oven is operated and on this frame-work myimproved oven heat regulator or instrument is mounted. The upper, innercorner of the frame-work has a small opening or aperture 19 thereinthrough which the forward short 'end 20 of a tubular thermostatic member21 having a relatively high co-eflicient of expansion projects, the rearend 22 of said member being projected outwardly through an opening 23 inthe rear oven wall. The forward end 20 of member 21 is rigidly securedto the frame 13 by a pair of clamp nuts 24 engaging the opposite sidesthereof -sleeve valve member 27. The valve member 27 is preferablytubular and has its upper portion rotatably journaled in a, cap 28closing the upper end of a housing 29, the lower end of Whichis threadedin a base member 30 in register with a recess 31 therein. The lower endof the valvemember 27 is disposed in the recess" 31 and is rotatableover a normally stationary valve member 32- which is 'adjustably mountedin the base member. provided with complementary ports or openings 33 and34, respectively, adapted to align Thevalve members 27 and 32 areand'disalign'upon rotation of the member 27, in the manner hereinafterdescribed. I

The base member 30 is firmly secured to i the frame-work 13 by a strapor bracket 1 member 35, see Figures 1, 2, 3, 7 and 10,

whereby the unit is rigidly secured to the J frame-work of the oven bythe members 25 and 35with the rear ends of the member 21 and 36'free ofthe oven. As will be readilyobviousthe member 21 is influenced by theheat within the oven 12 and expands or contracts as the oven temperatureraises or falls and this contraction or expansion is imparted to thevalve member 27 through a member 36 having a relatively low co-efficientof expansion and towhich the member 21 has its end 22 firmly secured .bya connecting member 37. The member 36 is preferably disposed outwardlyof the oven in a' neutral zone and out of the range of the influenceofthe oven heat and has its forward end 38 directed inwardly andflattened, as at 39, for pivotal connec tion between the adjacentbifurcations of a crank member 40 by a removable pivot pin' 7 4 1. Thecrank 40 is fixed tothe trunnion 26 and has two complementary ends topermit the application of the instrument to either a right or left handoven without requiring special parts.

The forward end ofmember 21 being made fast to the rigid frame 13 of theoven and the rear end thereof being rigidly connected with the member36, converts the longitudinal contraction and expansion of the member 21to rotary motion at the valve member 27, aligning and disaligning theports 33 and 34 to vary the volume of gas flowing therethrough, ashereinafter described. l

The member 30 is provided with a central bore or well 41 int-he upperend thereof communicating with recess 31 and a recess a2 in the lowerportion of the base member.

41, while the collar 44 is loose on the eXten-' sion 45 and beingadjusted, by a spring 48 confined between a washer 49 secured to theextreme lower end of the-member 32 by a screw 50 and the collar member.The upper face of the collar member is preferably counter-bored toreceive a circular boss or enlarged portion 51 on the under-face of thebase member. i

The gas cock 17 is of special construction, the gas instead of flowingdirectly from the stringer 16 to the manifold 18, flows first throughthe control valve hereinbefore described, thence back through the gascock and into the manifold. This is accomplished by providing the gascook with auxiliary outlet and inlet ports 52 and 53 respectively,

whereby movement of the gas cock plug 54 by its handle 55 to openposition registers the port 52 with the stringer 16 and the port 53 withthe manifold 18. The auxiliary outlet port 52 has a coupling tube 56connected therewith, in which one end of an extensible tube 57 istelescoped and adjustably secured therein by a binding cap or head 58threaded over the end of tube 56. The head 58 has a port 58' adapted toride over the outer tapered'end 59 of the tube 57 to secure the same inadjusted position in tube 56 to prevent the leakage of gas therepast.The other end of tube 57 is adjustably telescoped in one endof an'L-coupling 60' and adjustably secured therein by a head 58 and theother end of the L-coupling has one end of a tube similar to the tube 57adjustably telescoped therein, the other .end of which is adjustablytelescoped in a coupling 61 communicating with the recess 42, saidsecond tube 57 having its endsadjustably secured in the couplings 60,and 61 by heads 58.

' A coupling 62 leads from the recess31 and has one end of a tube 57',similar to the tube 57, telescoped and adjustably secured therein by ahead or cap 58, the other endof-which is telescoped and adjustablysecured in one end of an L-shaped-tube or coupling 63 by a head or cap58. The other end of coupling 63 has one end of a second tube 57telescoped and adjustably secured therein by a head or cap 58', theother end of the second tube 57 being telescoped and adjustably securedin a coupling tube 56' connected with the auxiliary inlet 53.

An opening of the valve plug 54 permits the gas to flow from thestringer 16 throu h the outlet 52 to the recess 42, thence into t einterior of the valve member 32, through ports 64 therein, through ports33 and 34, if the same are in alignment, into the interior of thehousing 29, thence into the recess 31, through tubes 62, 57, 63, 57 and56', the

inlet port 53, manifold 18 and thence to the facilitates the regulationof the volume of gas supplied the burner through the by-pass.

The valve member 32 is normally stationary and the valve member 27 isrotatedby the expansion and contraction of member 21, to align anddisalign the ports 33 and 34 to maintain a flame at theburner sufficientto keep the oven temperature at any predetermined degree which may beset by adjusting the normally stationary valve member 32. Valve member32 is rotated to any desired position of adjustment by a setting screw68 threaded in a lug or ear 69 on the base 30 and having its inner endabutting a projection or lug 70 formed on the collar member 44, saidscrew being provided with a knob or adjusting wheel 71 on its outer end.The lug 70 is yieldably maintained in engagement with the inner end ofthe screw 68 by a spring pressed plunger 72,mounted in the bore of a lugor car 73 carried by the base 30 diametricallyv opposite ear 69, betweenwhich and a removable cap 75 a spring 74 is confined. The spring pressedplun er 72 in addition to maintaining the lug 0' and the screw 68 inengagement at all times maintains all play or lost motion to one side tothus increase the accuracy of the'instrument. Y

The knob 71 is readily adjustably secured to the screw shaft 68 by asetscrew 71' and carries a cylindrical dial or disc 76 provided on itsperiphery with two sets of figures 77 and 78, see Figure 4, forartificial and natural gas, respectively. 'To prevent confusion, ashield member 79 is provided which is movable to cover either one ofsaid sets of figures. As is well known in the art, natural gas has ahigher B. t. u. than artificial gas,thus requiring a lower-volume of gasto maintain a set degree of heat in the oven when natural gas is usedand a greater volume to maintain any set degree of heat 'When'artificial gas is required, For this reason the compound dial isemployed and the shield 79 moved to cover up the artificial reading whenthe device is used for natural gas, and vice versa. But one turn of theknob 71 is required to operate the instrument from minimum to maximumheat and the dial carries a stop 72 which cooperates 5 with a stop 73carried by the base member to prevent rotation of the knob more than oneturn.

Three means are provided for setting the instrument after the same hasbeen applied toa stove, one, the connecting member 37,

which is preferably in the form of an adjustable clamp, another. thecollar member 44: and the other the set screw 71. After the instrumenthas been applied to the oven, the burner is ignited and after-the ovenhas become heated a thermometer reading is taken. Assume the thermometerreading to be three hundred degrees, either the connecting member 37 maybe loosened and the knob 71 rotated to align the designation 300 with apointer 80 carried by the base member and the connecting member thenmade fast again; the binding screw 47 of the collar member loosened andthe knob 71 rotated to align the designation 300 with the pointer 80 andthe screw 47 then turned to make the collar member fast to the screwshaft 68, or the set screw 71 loosen and then tightened to make the knob71 and its dial fast to the screw shaft 68. All of these adjustments arelocated exteriorly of the oven out of the range of the oven heat and aremade under atmospheric conditions rendering them absolutely accurate.

As an added factor of safety against extinction of the burner, a pilotis provided, as best illustrated in Figure 6. The'pilot comprises a tube85, the outer end of which is connected with the coupling 60, as at 85',

and the inner end of which is in the form of a pilot tip 81, preferablyconstructed of Monel, or other similar metal. The pilot tip has anorifice 87 therein at which a pilot flame burns and the size of thepilot flame is adjustable from the front of the oven by a knob 82 fromwhich a flexible shaft 83 leads having a threaded enlargement 84 on itsinner end in threaded engagement with the pilot tip. Anextension orneedle valve member 86 of Mon'el or other similar metal pro'ects fromthe enlargement 84 to the ori ce whereb the area of the orifice may bereadily ad uSted to regulate the size of the pilot flame. Theenlargement 84 is longitudinally grooved to permit the flow of gasthereby and the adjusting of the orifice opening by the meansillustrated insures the to maintenance of the proper pressure at thepilot and prevents a variance in the pilot in the event the shaft 83 iseffected by temperature changes as its contraction and expansion isrearwardly of the needle ,valve member 86.

The upper end of the valve structure proper and the outer ends of themembers 21 and 36 are preferably enclosed in a housing 88 and theouter-most portion of said housing has a fiat surface inclined withrespect to the perpendicular and provided. with various figuresrepresenting the degrees of heat to the side which is delineated the usefor which the oven is adapted at such degrees to assist the operator insetting the device. As for example, should the operator desire to setthe oven for baking bread, a glance at the top of the housing 88,discloses that 400 degrees is the temperature required and the knob 71is rotated to align the 400 degree designation of the dial 76 with thepointer 80.

With the oven thus set for 400 degrees, the gas cook 17 is opened andthe burner 15 ignited. The oven being practically cold and the member 21fully contracted ports 33 and 34 are in full alignment and the burner 15supplied with the volume of gas necessary to burn at full maintenance.As the temperature of the ovenapproaches 400 degrees, the member 21.rotates, the valve member 27 through the neutral member 36 graduallyclosing the opening of ports 33 and 34, thus diminishing the supply offuel to't-he burner in proportion to the increase in the temperature ofthe oven.

To insure the instant response of the instrument to any slight variationin the temperature of the oven the members 21 and 36 are preferablytubular, having their rear ends open to the atmosphere and their forwardends provided with relatively small openings 89and 90, respectively,permitting the constant passage of air therethrough. The circulationthrough the members 21 and 36 is from the rear to thefront, as theopenings at the rear are ofa greater area than those at the front.The'circulation of air through the member 21 is accelerated bytemperature changes taking place within the oven. The air passingthrough mem ber 36vassists in maintaining it at a constant temperatureand the air passing through the member 21 insures its instant responseto any drop in temperature in the 115 oven, as will be readily apparent.

This construction absolutely eliminates 'the use of springs againstwhich a thermostatic member must work, as is the case in the majority ofthermostatic oven heat regulators now on the market and eliminates avalve member in which the force of gravitymust be contended with.Furthermore the gas is at all times kept out of the oven.

In Figure ,10 a slightly modified construction is illustrated in whichthe members 27 and 32 vertically reciprocate instead of rotate. Thesetting of the device is accomplished by the screw 68 engaging againstone arm 91-of a bell crank lever 92 pivotally 1B0 meager mounted, as at93, to the base member, the influenced by the heat of the oven, meansother arm 93 of which is ivotally connected with the lower end of hemember 32, as at 94. The member 32 in this embodiment of my invention,is normally urged outwardly of the base member by a spring 95 confinedbetween a flange 96 on the lower end thereof and the wall of the basemember to maintain the bell crank arm 91 in constant engagement with theinner end of the screw 68. v

In this form of my invention, the member 36 converts the contraction andexpansion of member 27 into reciprocal movement by having its end 38pivotally connected, as at 97, with one arm of a bell crank lever 98pivoted, as at 99, to the cap 52. The other arm of the bell crank ispivotally connected, as at 100, with the upper end of the trunnion 26which is slidably extended through the cap member 25. As the'operationof this form of'my invention is substantially identical with thatillustrated in Figures 1 to 8,

inclusive, further description thereof is drawn perpendicularly throughthe outermost portion of the stringer. As a result,

' it is unnecessary to make special provision in the crating of thestoves for shipment, thus effecting an economy in material and labor inthe cratin and facilitating the general handling of t he stove.

' Furthermore, the control of the gas flowing to the 'oven burner 15being directly from the gas cook 17 eliminates special fittings and longlengths of pipe, producing an economy in material and labor in themanufacture and application of the control andmaterially simplifying itsinstallation, inasmuch as it is only necessary to provide a smallaperture in the frame 13 anddn the rear oven wall and replace theconventional gas cock of the oven burner with the special; gas cockillustrated,

The telescoping and adjustable tubes 57 and 57 make it possible to applythe instrument to either right or left hand stoves without any change intheir construction and provide for universal adjustments laterall andvertically and at various angles, eliminating the necessity of providingmeans to insure positive truing'of the various parts duringinstallation.

What I claim as my invention is:

1. In a device of the character described including an oven having asubstantially rigid frame at one side and a burner for heating theinterior thereof, means for regulating the flow of fuel to the burner inproportion to the temperature of said oven and including a member havinga relatively high co-eiiicient of expansion and adapted to be connectingone end of said member with said rigid oven frame, the other end of saidmember being passed outwardly of the oven, a second member having arelatively low coefficient of expansion and positioned in a neutral zoneout of the influence of the heat of the oven, means connecting thesecond member with the first-mentioned member, a control valveforregulating the flow of fuel to the oven burner, and a connectionbetween.

heating the interior thereof, means for regu- 1 lating the flow of fuelto the burner in proportion to the temperature of said oven'andincluding a member having a relatively high co-eificient of expansionand adapted to be influenced by the heat of the oven, means connectingone end of said member with said rigid oven frame, the other end of saidmember being passed outwardly of the even, a second member having arelatively low co-eliicient of expansion and positioned in a neutralzone out of the influence of the heat of the oven, means adjustablyconnecting the second member with the first-mentioned member, a controlvalve for regulating the flow of fuel to the oven burner, and aconnection between said control valve and said second member wherebyexpansion of .said first-mentioned member decreases the flow of fueltothe burner and contraction of said first-mentioned member increases theflow of fuel to said burner.

a 3. In a deviceof the character described including an oven having asubstantially rigid frame at one side and a burner for heating theinterior thereof, means for regulating .the flow of fuel to the burnerin proportion to the temperature of said even and including a memberhaving a relatively high co-eflicient of expansion and adapted to beinfluenced by the oven heat, means connecting one end of said memberwith said rigid oven frame, the other end of said member being passedoutwardly of the oven, a second member having a relatively lowco-eflicient of expansion and positioned in a neutral zone out of theinfluence of the heat of the oven, means connecting one end of wasfirst-mentioned member decreases the flow of fuel to the burner andcontraction of said first-mentioned member increases the flow of fuel tosaid burner.

v 1. In an applianceof the character de-. scribed including an oven, aburner for the oven and av valve for regulating'the flow of .fuel to theburner, a thermostatic member the interior of said oven, and meanspermitting thecirculation of air fromthe exterior of'said oven throughsaid tube whereby said q the temperature of theoven.

tube member instantly responds to a fall in '6. In an appliance of thecharacter described including an oven, a burner therefor and a valve forregulating the flow of fuel to the. burner, a thermostatic member foractuatin saidvalve and including a tubular mem er having a relatively'high 00- efiicient of expansion and positioned within the interior ofthe oven, means permitting the circulation ofalr through said member, asecond tubular member mounted exteriorly of the oven and having arelatively low co-eflicient of expansion, means connectin thesecond'member wlth the first-mentioned 7 member, means connecting saidsecond member with the burner control valve, and means permitting thecirculation of air through said second member whereby the temperaturethereof is maintained substantially con stant. i a

7.111 a device of the character described including an oven and a burnerfor heating the same, a valve member for controlling the flow of fuel tosaid'burner, a member dis-' posed within the oven and having arelatively high co-efiicient of expansion, a second member disposed;exteriorly of the oven and having a relatively low co-eficient ofexpansion, means connecting said; members wherebyexp'ansion andcontraction of said first member shifts both of said members in the sameplane, and a connection between said second member and-thecontrol vailvewhereby movement of said secondrmember ,actuates thecontrol valve.

8. In a device of the character described I including an oven and aburner for heating the same, avalve member for controlling the flow offuel said burner, a member disposedwithinthe oven and having arelatively high {co-efficient of expansion, a second member-disposed,exteriorly of the oven and having a.relatively low coefiicient ofexpansion, 'means connecting said members .whereby expansion andcontraction of said first member sh1fts the. second member, a

connection between said, second member and the control valve wherebymovement of said secondmember actuates the control valve, and meanspermitting the circulation of air through said second member whereby thesame is maintained at a substantially constanttemper'ature."

9. A device of the character described, comprising an oven, a burnertherefor, a source of fuel, a pair of freely rotatable telescopingtubular valve members, a liousing enclosing said tubular members, portsin said tube members adapted tic-register, means connecting the interiorof one member with the source of fuel and the interior of the housingwith the burner, whereby the volume of fuel supplied the burner iscontrolled by said'ports, and means actuated by a rise or fall in thetemperature of the oven to open and close said ports to regulate theflow of fuel to said burner.

10. A device of the character described,

comprising an oven, a burner therefor, a

source of fuel, a pair of telescoping tubular .valve members, a housingenclosing said tubular members, ports insaidtubular members adapted toregister, means connecting the interior of one member with the source'of fuel and the interior of the housing with the burner, whereby thevolume of fuel supplied the burner'is controlled by said ports, meansactuated by a rise or fall in the temperature of the oven to move one ofsaid telescoping members and open or close said ports to control thevolume of fuel supplied the burner through said ports, andmanuallyactuated means for adjusting the other of said telescoping members. r

11. In an appliance of the character described including an oven, aburner and a fuel supply therefor, means for adjustably connecting theburner with its fuel supply and including a valve member, a member disosed in the oven and having a relativeigh co-eficient of expansion, theforward end of said member being projected through the oven front walland the rear end of said member being projected through the rear wall ofthe oven, means connecting the forward end of said member with the valvemember, a second member positionedexteriorly of the oven and having arelatively low co-efiicient of expansion, means connecting the rearendof said second memberwith the rear end of the first member, and meansconnecting the forward endof said second member with the valve memberand telescoping whereby expansion or contraction of said first-mentionedmember shifts the second member and actuates the valve member.

12. In a gas stove having an oven, a burner for the oven and a gas cockfor connecting the same to a gas supply, said gas cock having two inletsand two outlet ports,

'one outlet port being connected with the comprising an oven, a burnertherefor, a-

source of 'fuel, a pair of freely rotatable tubular valve members, a

housing enclosing said members, ports in said tube members adapted toregister for the passage of fuel therethrough, means.

connecting the interior of: one member with the source of fuel and theinterior of the housing with the burner whereby the volume of fuelsupplied to the burner is controlled before flowing to the meager onevalve member with respect to the other,

- and automatic means actuated by a rise and fall of the temperaturewithin the oven for moving the second valve member with respect to thefirst to open and close said ports, v

14. A device of the character described including an oven, a burnertherefor, a source of fuel supply and a valve for connecting the burnerwith the supply, a bypass through which the fuel pass prior to itspassage from the valve to the burner, a valve positioned within saidby-pass for controlling the flow of iuel'to the burner, said valveincluding a stationary casing having therein a manually adjusted valveportion, a second valve portion fitting over the first saidvaive'portion, ports in said valve portions adapted to register for thepassage of fuel therethrongh, and automatic means positioned within theoven and connecting to one of said vah'e portions for controlling theflow of fuel to the burner on the rise and fall of the temperature with-,in the oven.

In testimony whereof I afix my signature.

EMIL L. CLAUS.

